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United States Patent | 5,136,559 |
Nakayama | August 4, 1992 |
In an apparatus for recording and reproducing optical information, a light beam from a semiconductor laser is reflected by a rotatable tracking mirror and is converged by an objective lens disposed on a carriage to form a small light spot on an optical information recording medium so as to perform recording, reproducing and erasing operations of the information. This apparatus includes a position sensor mechanism disposed near the tracking mirror and detecting a rotary position of the tracking mirror; a carriage control mechanism disposed near the tracking mirror and controlling the movement of the carriage based on an output signal from the position sensor mechanism so as to correct an incident angle of the light beam incident to the objective lens; a light source disposed in the position sensor mechanism and fixed to a rear face side of the tracking mirror with respect to a reflecting face thereof such that the light source is rotated integrally with the tracking mirror; and a light-receiving element disposed in the position sensor mechanism and outputting a signal indicative of a rotary angle of the tracking mirror to the carriage control mechanism by receiving light emitted from the light source.
Inventors: | Nakayama; Masahiko (Yokohama, JP) |
Assignee: | Ricoh Company, Ltd. (Tokyo, JP) |
Appl. No.: | 491173 |
Filed: | March 9, 1990 |
Mar 30, 1989[JP] | 1-36858[U] |
Current U.S. Class: | 369/44.11; 360/78.05; 369/44.15; 369/44.32; 369/119 |
Intern'l Class: | G11B 007/00 |
Field of Search: | 369/44.15-44.21,32,112,119,118,120,44.11,53,54,44.25,44.32,44.29 360/78.05,78.01,78.12 |
4607358 | Aug., 1986 | Maeda et al. | 369/32. |
4736353 | Apr., 1988 | Kasai et al. | 360/78. |
4744071 | May., 1988 | Bricot et al. | 369/44. |
4782474 | Nov., 1988 | Arai et al. | 369/44. |
4815059 | Mar., 1989 | Nakayama et al. | 369/45. |
5010537 | Apr., 1991 | Ohkuma et al. | 369/54. |
Foreign Patent Documents | |||
0079943 | Mar., 1989 | JP | 369/112. |